Analysis of human arm characteristics in cooperative motion based on musculoskeletal model

Human characteristics are supposed to be applied to the control systems of the human-friendly robots. Therefore, it is important to know the human characteristics in man-machine cooperative tasks. In this study, we considered a rotational one degree of freedom experimental system as well as a mass-spring-damper-friction dynamic model for the human arm, and analyzed the characteristics of the human arm with the effect of the gravity load. We compared this cooperative motion with the study without the gravity load. As the result, we found that the damping and friction characteristics remained unchanged and the spring characteristics disappeared. In this case, the characteristics of the follower's arm had no relationship with the weight of the load.